Ampeg SVPCL - Manual (Page 7)

SVPCL Bass Preamp
7
Changing the Tubes:
Tube wear is in direct proportion to how often and how hard you play. Preamp tubes aren’t worked as hard as power
tubes and typically last longer. When a preamp tube wears out, the preamp may squeal, get noisy, lose gain and sensitiv-
ity, or just quit working. A service center can determine which tube(s) may need replacing. To get to the tubes in the SVPCL,
the top must be removed. This should be left to a qualified service person.
System Block Diagram:
INPUT
PAD GAIN
MUTE
MUTE
TRANSFORMER
BALANCED LINE
OUTPUT
PEAK
MID
MID FREQ.
MASTER
POST
PRE
BUFFER
PREAMP
OUTPUT
PREAMP
OUTPUT
GND
LIFT
TUNER
OUTPUT
ULTRA
HIGH ULTRA LOW
BASS TREBLE